Private Branch Exchange (PBX)
A private branch exchange (PBX) is an electronic phone system serving a particular business or office. A typical PBX has a number of individual “extension” lines connected to phones in the organization and a fewer number of “trunk” lines connected to a circuit-switched phone network such as the public switched telephone network (“PSTN”). On the expectation only a small number of the total number of phones in the organization will be connected on a phone call over the circuit-switched phone network at the same time, the PBX allows the numerous extension links to share the fewer trunk lines, thereby saving the organization the expense of a dedicated phone line to the circuit-switched phone network for each phone in the organization.
Modern PBXs provide voice over internet protocol (“VoIP”) capabilities allowing phones and other computing devices in an organization to send and receive voice, video, and other data over a packet-switched data network in Internet Protocol (“IP”) network packets. Many of these PBXs also interoperate with a circuit-switched phone network to facilitate phone calls between VoIP phones connected to the packet-switched network and analog or cell phones connected to the circuit-switched phone network.
A recent trend in phone systems for businesses and organizations is that of the “hosted PBX”, also referred to as a “virtual PBX” or “cloud PBX”. A hosted PBX is a hosted service operated by a service provider that provides PBX functionality to multiple business and organizations. However, it appears to each business and organization that they have a dedicated PBX. The hardware and software implementing the hosted service is typically located in and operates in one or more data centers or other hosting facilities separate from the business and organizations using the hosted service and to which the business and organizations are connected, typically by a packet-switched data network such as the Internet.
Call Parking
One call convenience feature provided by many PBXs is known as “call parking”. As typically implemented by a PBX, call parking allows a caller to place an active call on hold from the caller's phone and have that call resume from a different phone, perhaps by a different party. The caller parking the call may be referred to as the “parker”. The party that resumes the parked call may be referred to as the “unparker”. After parking the call, the parker's phone is disconnected from the call, but the call is not terminated. The parker does not need to wait for the parked call to resume before the parker can hang up his or her phone. A PBX typically implements call parking by assigning the active call to an unused extension which is then displayed on an interface of the parker's phone. The parked call is then resumed at another phone by the unparker by connecting the other phone to the assigned extension.
To notify others of a parked call, the parker typically announces the assigned extension over a public address system. For example, a cashier at a grocery store may receive a call from a customer for the bakery. Upon receiving the call, the cashier may park the call and announce over the grocery store's public address system “call for bakery on extension 9000”. Thereafter, someone in the bakery may unpark the call from a phone in the bakery area of the store.
Unfortunately, notification by public address system is impractical in many situations. For example, many offices, businesses, and organizations are not outfitted with a public address system. Further, the parker may wish to park the call for a phone at location distant from the parker's phone. Further still, the parker may not know the current location of the intended unparker.
Some PBXs allow the parker to enter the extension of a particular phone to signal. These PBXs then signal the particular phone to notify of the parked call. For example, the PBXs may ring the particular phone and/or cause a light of the particular phone to flash or illuminate. However, this is ineffective if no one is near the particular phone to hear or see the signal or if the parker is unsure of which particular phone to signal.
Accordingly, there is a need for phone systems with call parking features that implement more reliable and convenient techniques for notifying persons of parked calls.